How to configure express to use dotnet core localhost SSL certificate?

Question

I run a dotnet 5 web api application which I want to call from my express web app. Think of it as a backend running on net5.0 and a front-end with a server running on nodejs and express.

My dotnet app uses a localhost certificate it generated and runs on https://localhost:5003.

My express app hosts a svelte front-end and runs on http://localhost:5005 (remark that the express app is not running on https). When I call my server I do something like:

const express = require('express');
const app = express();
const http = require("http");
const port = process.env.PORT || 5005;
const cors = require('cors');
const axios = require('axios');
const settings = require("./../settings");

const httpAgent = new http.Agent({
    // something needs to happen here!
});
axios.default.options = httpAgent;

// parse application/json
app.use(express.json());
app.use(cors());


app.post("/api/login", async (req, res) => {
    console.log(req.body);

    const { name, password } = req.body;

    var loginResponse = await axios.post(settings.server.url + "api/login", {
        userName: name,
        password: password
    });

    console.log(loginResponse);

    res.send(loginResponse);
});

The error I get is:

(node:15896) UnhandledPromiseRejectionWarning: Error: self signed certificate
    at TLSSocket.onConnectSecure (_tls_wrap.js:1507:34)
    at TLSSocket.emit (events.js:376:20)
    at TLSSocket._finishInit (_tls_wrap.js:932:8)
    at TLSWrap.ssl.onhandshakedone (_tls_wrap.js:706:12)

I've found this question and some other ones, not worth mentioning atm, but I keep running up against blocks and I really do not want to "just ignore the certificates".

My localhost certificate is installed and I can find it in de certificates of my machine. I can't, however, physically find it on my machine searching for "localhost.crt".

My question is: How can I set up my httpAgent, so that when I use axios to call my back-end I call it using its https endpoint and not get an error?